1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 /* 23 * Copyright 1989 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 /* Copyright (c) 1984 AT&T */ 28 /* All Rights Reserved */ 29 30 #pragma ident "%Z%%M% %I% %E% SMI" 31 32 #include <fcntl.h> 33 #include <unistd.h> 34 #include <errno.h> 35 #include <sys/syscall.h> 36 37 /* 38 * convert lockf() into fcntl() for SystemV compatibility 39 */ 40 41 /* New SVR4 values */ 42 #define SV_GETLK 5 43 #define SV_SETLK 6 44 #define SV_SETLKW 7 45 46 int 47 lockf(int fildes, int function, long size) 48 { 49 struct flock ld; 50 int cmd; 51 52 cmd = SV_SETLK; /* assume non-blocking operation */ 53 ld.l_type = F_WRLCK; /* lockf() only deals with exclusive locks */ 54 ld.l_whence = 1; /* lock always starts at current position */ 55 if (size < 0) { 56 ld.l_start = size; 57 ld.l_len = -size; 58 } else { 59 ld.l_start = 0L; 60 ld.l_len = size; 61 } 62 63 switch (function) { 64 case F_TEST: 65 if (_syscall(SYS_fcntl, fildes, SV_GETLK, &ld) != -1) { 66 if (ld.l_type == F_UNLCK) { 67 ld.l_pid = ld.l_xxx; 68 /* l_pid is the last field in the 69 SVr3 flock structure */ 70 return (0); 71 } else 72 errno = EACCES; /* EAGAIN ?? */ 73 } 74 return (-1); 75 76 default: 77 errno = EINVAL; 78 return (-1); 79 80 /* the rest fall thru to the fcntl() at the end */ 81 case F_ULOCK: 82 ld.l_type = F_UNLCK; 83 break; 84 85 case F_LOCK: 86 cmd = SV_SETLKW; /* block, if not available */ 87 break; 88 89 case F_TLOCK: 90 break; 91 } 92 if (_syscall(SYS_fcntl, fildes, cmd, &ld) == -1) { 93 switch (errno) { 94 /* this hack is purported to be for /usr/group compatibility */ 95 case ENOLCK: 96 errno = EDEADLK; 97 } 98 return(-1); 99 } else { 100 ld.l_pid = ld.l_xxx; /* l_pid is the last field in the 101 SVr3 flock structure */ 102 return(0); 103 } 104 } 105